Electric indicator.



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ELECTRIC INDICATO APPLICATION FIL EO OCT- B.

1,241,151. Pate dSept. ,1917.

hens-s In ven tor:

H. H. RIGGS.

ELECTRIC INDICATOR.

nrucmon mm act. I. 1913.

1 ,241, 1 5 1 v Patented Sept. 25, 1917.

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MY; nzss Q's lnvevit-on' UNITED STATES PATENT QFFICE.

HENRY H. RIGGS, 0F KHARPUT, TURKEY.

ELECTRIC INDICATOR.

Application filed October 8, 1913.

To all whom it may concern:

Be it known that I, HENRY HARRISON RIGGS, a citizen of the United States, residing at Kharput, Turkey, have invented a new and useful Electric Indicator, of which the following is a specification.

The object of my invention is to provide simple means by which the positions of a lever, wheel or other rotating member may be indicated for observation at a point or points distant therefrom. I attain this object by the device illustrated in the accompanying drawing, in which:

Figure 1 is a general plan view of the entire mechanism, with wiring represented diagrammatically; Figs. 2 and 3 show the apparatus in two typical positions, and Fig. 4 shows a modification of the commutator fingers, and the action of that modification; Fig. 5 A and B are diagrams showing the wiring between transmitter and receiver in any supposable case. Fig. 6 is a vertical cross section taken along the line a--b on Fig. 1, viewed from the right, unnecessary parts bein omitted for the sake of clearness, Similar characters of reference refer to similar parts throughout the several figures.

' The device is composed of two parts, a commutator, A, and an indicator, B, connected by wires, and supplied with current from a battery or other source, 16. The moving rotating member, whose positionsit is desired to indicate, is shown at 7; for convenience a simple arm is shown, rotating about the axis 10. Attached to this arm, and moving with it, are two brushes, 8 and 9. 'Brush 8 is electrically connected with the arm 7, and throu h it with the axis 10. Brush 9 is insulated rom the arm 7.

These two brushes are slit into fingers which contact with a commutator composed of a number of segments, 1, 2, 3, 4, 5, and two rings, 6 and 30, ring 30 being in electrical connection with the axis 10. The number of segments is determined b the number of coils in the indicator, (which is described below), the number of segments being always one more than the number of coils. The segments are unsymmctrically disposed upon the commutator, two of the segments, 2 and 5, being half as wide as the remaining segments; and the wider segments are so placed that the center of each falls diametrically opposite to the line of division between two opposite segments.

Specification of Letters Patent.

Patented Sept. 25, 1917.

Serial No. 794,148.

Brush 8 has two fin ers, whose combined width makes an are 0 contact on the commutator equal to one-half of the width of one of the narrower segments of the commutator and a third finger contacting only with ring 30. Brush 9 has two similar fingers, diametrically opposite to the corresponding fingers of brush 8, and also a third finger contacting only with the ring 6. The ring 6 and the axis 10 are connected, respectively, to the two poles of a battery or other source of current, so that as the arm 7 rotates, current of opposite signs is delivered by the two brushes to the segments with which they successively contact. A switch or push-button 15, in the battery circuit, permits or leaving the circuit open if desired, closing it only when the indicator is to be observed. I

The segments of the commutator are connected, by suitable conductors, to the coils in the indicating device as follows :Designating the two terminals of each coil as the entering and the outgoing terminals respectively,the entering terminal of coil 19 is connected to segment 5; the outgoing terminals of coils 19 and 20 to segment 3; the enteringterminals of coils 20 and 21 to segment 1; the outgoing terminals of coils 21 and 22 to segment 4:, and the enterin terminal of coil 22 to segment 2.

if the number of coils is more or less than four, in general the arrangement of the segments and their connection with the coils is the same as if the commutator were first divided into twice as many segments as there are coils in the indicator; the two terminals of each coil being connected to diametrically opposite segments, successively in the order in which the coils stand as shown in Fig. 5; and then the segments connected with adjacent coils being joined together in pairs, always provided that each pair of segments so united falls diametrically opposite to the line of division between two segments or pairs of segments, and not symmetrically opposite to another pair of segments so united as shown in Fi 5.

he coils, 19, 20, 21, and 22 are wound on soft iron cores, 27, which are fixed vertically in a soft-iron plate, 28, which is the yoke of the magnet and forms the base of the indicator (see Fi 6). The excitation of one or more of t ese coils produces a brush contacts with two segments,

directed in the plane of the poles of the cores '27 by the curved soft iron pole-piece 23, which is also vertically fixed to the base plate 28, and rises to the same height as the cores 27.

In the magnetic field so formed a short, lozenge-shaped needle, 24, of magnetized steel, is mounted so as to rotate freely in a plane parallel to the base 28. This needle is fixed on an arbor 25, one end of which is journaled on the plate 28, while the other end projects through a bearing in the arm 26, which is suita Y supported on the base or the containing case of the instrument. On the outer end of the arbor 25 is fixed a pointer 18, which therefore moves with the needle 24, and indicates its position on the scale or card 17. Reference to the din-- grams in Figs. 2 and 3, as well asto Fig. 1, will show tie operation of my invention. \Vhen, as in Fig. 2, each brush contacts with only one segment of the commutator, current is furnished to but one coil, magnetizing its core; the unlike pole of the needle 24 then points to the pole of that coil, as shown, Fig. 2. When, as in Fi 3, one of the brushes contacts with two ad'acent segments at once, the other brush touching but one segment, the two coils connected with all three segments are similarly excited, and the needle assumes a position midway between the two poles. If, as in Fig. 1, each (which is only possible when two of the segments involved are connected with coils at the ends of the series, 19 and 22,) those terminal coils are dissimilarly excited, and attract opposite ends of the needle 24 with equal force, so that the needle takes up a position equally distant from both. It will be seen from these typical cases that wherever the arm 7 may be pla d, the needle and its attached pointer immediately assume a corresponding position, irrespective of the direction in which the arm 7 may have been moved. The number of positions possible for the pointer 18 is four times the number of coils or windings in the magnet.

It is sometimes desirable to have the motion of the indicator more nearly continuous. For this purpose I provide brushes for the commutator which, instead of two fingers, are divided into a large number of fingers, each having a resistance relatively high as compared with that of the coils. The operation of this modification is shown diagrammatically in Fig. 4. When the brush overlaps the boundary of two segments of the commutator, current is sup plied to each segment in proportion to the number of fingers in contact with it. In that case the needle assumes a position pointing nearer to the coil which receives the greater amount of current. If the brush is made just as wide as one of the narrow segments, and is divided into a large number of fingers, the motion of the pointer becomes practically continuous, and follows closely the motion of the rotating member or arm.

It is obvious that the principle on which my invention operates is quite independent of details of construction, such as the form of the commutator, brushes, magnet cores, etc. the number of coils may be more or less than four, and the number of segments likewise. The wiring may be continued toconnect up to one commutator any desired number of indicators in series or in parallel. The device may be applied directly or indirectly to any desired rotating or moving object, the arm 7 of the specification being connected with the moving member or identical with it. For example, if the arm 7 is suitably attached to the hoisting mechanism of an elevator, an indicator on each floor will show the position of the car. If the arm 7 is connected by rack and pinion or by cord and pulley to a float, one or more indicators at an point desired may indicate the height of uids in a tank, reservoir or river. A ain, the arm 7 being connected to the mid er of a shi the indicator can tell the helmsman exact y how far his steering engine has turned the rudder. Or, if the arm 7 be moved over a dial, and a similar dial be provided on the indicator at a distant point, the apparatus may be used as a tele ra h, such as a ships telegraph between ri go and en inc-room. All of these are merely illustrations of the possible uses of this device; others mi ht be mentioned, all of which fall within the scope and intention of my invention, so far as it is reasonably applicable.

What I claim, and desire to secure by Letters Patent is 1. In an electric indicator, an electromagnet havin a plurality of windings on poles arrange in a semi-circle alternately connected together in pairs of like polarity, and a ma netic needle rotatably mounted in the fiel of force of said electro-magnet, substantially as shown.

2. In an electric indicator, an electromagnet having a plurality of active poles arranged in a semicircle, and a curved polepiece in effect completin the circle, with a magnetic needle rotatal ly mounted within that circle.

3. In an electric indicator, an electromagnet having a plurality of windings arranged m a semicircle, a rotating member, and means operated by the rotating member to furnish current to said windings successively, in one direction during one half of the rotation of said rotating member, and in the opposite direction during the other half of the same rotation.

i. In an electric indicator, an electromagnet having a plurality of windings arranged in a semicircle, a rotating member, and means operated by the rotating member to furnish current alternately to single windings and to pairs of adjacent windings, substantially as shown.

5. In an electric indicator, the combination of an electro-magnet having a plurality of active poles arranged in a semicircle, with a rotating member, a commutator adjacent thereto, said commutator being composed of a plurality of segments connected with the windings on the electro-magnet and a pair of rings, and a pair of brushes carried by the rotating member which take current from the rings and deliver it throu h the segments to the windings.

6. n an electric indicator, an electromagnet having a plurality of poles arranged in a semicircle, windings on said poles whose terminals are connected up alternately in pairs of like polarity, with a r0- tating member carrying a pair of brushes, :1 commutator on which said brushes contact, said commutator having two narrow and one or more broad segments, said broad segments being connected to said pairs of terminals.

7. In an electric indicator, an electromagnet having a plurality of windings on poles arranged in a semicircle with a curved polepiece in effect completing the circle, with a rotating member, a commutator adj acent thereto whose segments are connected with said windings, and a pair of brushes carried by said rotating member, said brushes having a plurality of contacting fingers of such high resistance that the amount of current furnished to each winding is determined by the number of fingers contaetin with the segment connected with that win ing.

HENRY H. RIGGS.

Witnesses MARY E. BARNUM, W. W. MSTERSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0." 

